Cryotherapy Reduces Inflammatory Response Without Altering Muscle Regeneration Process and Extracellular Matrix Remodeling of Rat Muscle

Pre-exercise cryotherapy reduces myoglobin and creatine kinase levels after eccentric muscle stress in young women

Introduction: The aim of this study was to investigate the effect of pre-exercise whole-body cryotherapy (WBC) on muscle damage indicators following eccentric treadmill exercise in young women. Methods: Twenty-seven participants underwent two 1-h downhill treadmill runs, replicating 60% of their maximal oxygen uptake, with a 4-week intermission for recovery and treatment application. In this intermission, one group underwent 20 sessions of WBC, delivered five times a week at -120°C for 3 min each, while the comparison group received no such treatment. Markers of muscle injury-serum myoglobin concentration, creatine kinase and lactate dehydrogenase activity and also uric acid, and cell-free DNA concentration-were measured before and after downhill runs. Results: The study observed a notable reduction in post-exercise myoglobin and CK levels in the WBC group after the second running session. Discussion: The results suggest that WBC can have a protective effects against muscle damage resulting from eccentric exercise.

The Effect of Physical Activity and Repeated Whole-Body Cryotherapy on the Expression of Modulators of the Inflammatory Response in Mononuclear Blood Cells among Young Men

Background: Series of whole-body cryotherapy (WBC) among healthy and physically active individuals can potentially reduce inflammatory response, although exact mechanisms remain unclear. Methods: The impact of whole-body cryotherapy on inflammation modulators among 28 young males, categorized as non-training (NTR, N = 10), non-training with WBC (NTR-WBC, N = 10), and training with WBC (TR-WBC, N = 8), is investigated in this study. Over a period of eight weeks, NTR-WBC and TR-WBC subjects underwent 24 WBC treatments (-130 °C for 3 min, three times a week), examining changes in mRNA expressions of IL-1A, IL-6, IL-10, IFN-G, SIRT1, SIRT3, SOD2, GSS, and ICAM-1. Results: The received data indicate an acute inflammatory response to initial WBC (increased IL-1A, IL-6, and SIRT), with a greater effect in NTR-WBC. Subsequent sessions showed enhanced expressions of antioxidative genes in both WBC groups, particularly non-trained, suggesting improved oxidative stress adaptation. A notable decrease in ICAM-1 mRNA post-24 WBC treatments in NTR-WBC signifies a potential systemic anti-inflammatory effect. Conclusions: The findings of the study suggest that the combination of regular physical activity with WBC administered three times per week can potentially modulate inflammatory and antioxidant responses. This modulation is evidenced by changes in the expression of genes related to these processes.

Rehabilitation Strategies for Wrist Pain in a Patient With Thalassemia Major and Distal Ulnar Hypoplasia: A Case Report

This case study examines the rehabilitation process of a 24-year-old female patient with thalassemia major (TM), a hereditary hemoglobinopathy, who also suffered from distal ulnar hypoplasia, a congenital anomaly that causes pain and affects the wrist joint's strength and range of motion. The patient underwent a comprehensive physical rehabilitation program that aimed to address the challenges posed by ulnar hypoplasia. This program included a combination of customized exercises, splinting, and orthotic interventions to improve hand and wrist function. By adopting a multidisciplinary approach, the patient experienced significant improvements in mobility, strength, and overall quality of life. This case highlights the significance of personalized rehabilitation strategies in managing complex medical conditions, demonstrating the potential for positive outcomes even in patients with dual diagnoses of TM and ulnar hypoplasia.

Immediate Effect of Cryo-Compression Therapy on Biomechanical Properties and Perfusion of Forearm Muscles in Mixed Martial Arts Fighters

Mixed martial arts (MMA) fighters use their arms and hands for striking with the fists, grappling, and defensive techniques, which puts a high load on the forearms and hand muscles. New methods are needed to decrease the risk of injury and increase the effectiveness of regeneration. This study aimed to assess the effectiveness of cryo-compression (CC) therapy of different times (3 and 6 min) on forearm muscles in MMA fighters by investigating muscle pain, stiffness, tension, elasticity strength, and perfusion. Twenty professional male MMA fighters aged 26.5 ± 4.5 years, with training experience of 10.3 ± 5.0 years, were enrolled on an experimental within-group study design. The participants underwent CC therapy at a temperature of 3 °C and compression of 75 mmHg for 3 min and, in the second session, for 6 min. The investigated parameters were in the following order: (1) perfusion in non-reference units (PU), (2) muscle tone (T-[Hz]), (3) stiffness (S-[N/m]), (4) elasticity (E-[arb]), (5) pressure pain threshold (PPT-[N/cm]), and (6) maximum isometric force (Fmax [kgf]) at two time points: (1) at rest-2 min before CC therapy (pre) and (2) 2 min after CC therapy (post). There were significant differences between 3 and 6 min of CC therapy for PU and T. Meanwhile, F, E, PPT, and S were significantly different when comparing pre- to post-conditions. These results provide evidence that CC therapy is a stimulus that significantly affects parameters characterizing muscle biomechanical properties, pain threshold, strength, and tissue perfusion.

Split-face study to evaluate efficacy of global cryomodulation for reduction of pain and inflammation after nonablative fractional resurfacing

OBJECTIVES

Cryomodulation, or the delivery of controlled cooling to downregulate inflammatory processes in the skin, has been proposed to mitigate acute side effects following various dermatologic treatments. A new controlled cooling device has been developed to deliver cryomodulation for a range of different indications. In this clinical study, we evaluate the device for the reduction of pain, erythema, and edema following nonablative fractional resurfacing (NAFR).

METHODS

A single-blind, prospective, randomized, split-face study was conducted to assess the efficacy of the controlled dermal cooling device for the reduction of pain, edema, and erythema following nonablative fractional resurfacing with the dual 1550 nm erbium-doped fiber and 1927 nm thulium fiber laser. Subjects were randomized to receive a 10-min controlled cooling treatment to either the left or right side of the face immediately following full face NAFR. Pain ratings were recorded immediately postlaser treatment and immediately postcryomodulation treatment. At follow-up, subjects were surveyed for reduction of side effects and treatment satisfaction. Blinded review of photographs by two physicians was conducted to assess efficacy.

RESULTS

The average pain score for subjects immediately post-NAFR was 5.15. Following cryomodulation, the average pain score on the treatment side was reduced by 69%, to an average of 1.6. The untreated side of the face was reduced by 19%, to an average of 4.2. Overall, 90% of subjects endorsed reduced discomfort. At follow-up, 70% of subjects reported a noticeable improvement in edema and 50% reported a noticeable improvement in erythema between the treatment and control sides. The average subject satisfaction score for the cryomodulation treatment was 4.2. All subjects (100%) indicated that they would elect to undergo the cryomodulation treatment again. Both blinded physician reviewers were successful in identifying the cryomodulation-treated side of the face in 70% of subjects' posttreatment photographs.

CONCLUSIONS

The results of this split-face study support the efficacy of a global cryomodulation device for the reduction of pain, edema, and erythema following NAFR treatment. Cryomodulation was delivered in a simple 10 min procedure and yielded high patient satisfaction.

Simulated altitude is medicine: intermittent exposure to hypobaric hypoxia and cold accelerates injured skeletal muscle recovery

Muscle injuries are the leading cause of sports casualties. Because of its high plasticity, skeletal muscle can respond to different stimuli to maintain and improve functionality. Intermittent hypobaric hypoxia (IHH) improves muscle oxygen delivery and utilization. Hypobaria coexists with cold in the biosphere, opening the possibility to consider the combined use of both environmental factors to achieve beneficial physiological adjustments. We studied the effects of IHH and cold exposure, separately and simultaneously, on muscle regeneration. Adult male rats were surgically injured in one gastrocnemius and randomly assigned to the following groups: (1) CTRL: passive recovery; (2) COLD: intermittently exposed to cold (4°C); (3) HYPO: submitted to IHH (4500 m); (4) COHY: exposed to intermittent simultaneous cold and hypoxia. Animals were subjected to these interventions for 4 h/day for 9 or 21 days. COLD and COHY rats showed faster muscle regeneration than CTRL, evidenced after 9 days at histological (dMHC-positive and centrally nucleated fibre reduction) and functional levels after 21 days. HYPO rats showed a full recovery from injury (at histological and functional levels) after 9 days, while COLD and COHY needed more time to induce a total functional recovery. IHH can be postulated as an anti-fibrotic treatment since it reduces collagen I deposition. The increase in the pSer473Akt/total Akt ratio observed after 9 days in COLD, HYPO and COHY, together with the increase in the pThr172AMPKα/total AMPKα ratio observed in the gastrocnemius of HYPO, provides clues to the molecular mechanisms involved in the improved muscle regeneration. KEY POINTS: Only intermittent hypobaric exposure accelerated muscle recovery as early as 9 days following injury at histological and functional levels. Injured muscles from animals treated with intermittent (4 h/day) cold, hypobaric hypoxia or a simultaneous combination of both stimuli regenerated histological structure and recovered muscle function 21 days after injury. The combination of cold and hypoxia showed a blunting effect as compared to hypoxia alone in the time course of the muscle recovery. The increased expression of the phosphorylated forms of Akt observed in all experimental groups could participate in the molecular cascade of events leading to a faster regeneration. The elevated levels of phosphorylated AMPKα in the HYPO group could play a key role in the modulation of the inflammatory response during the first steps of the muscle regeneration process.

Beyond Tissue replacement: The Emerging role of smart implants in healthcare

Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices.

Partial-body cryostimulation does not impact peripheral microvascular responsiveness but reduces muscular metabolic O2 consumption (mV˙O2) at rest

This study aimed to investigate the effect of partial-body cryostimulation (PBC) on microvascular responsiveness and muscular metabolic O2 consumption rate (mV˙O2). Twenty healthy young adults (ten males and ten females) underwent a post-occlusive reactive hyperemia (PORH) test at the flexor digitorum superficialis area before and after a 3-min PBC session and a 3-min control session. Using near-infrared spectroscopy, occlusion and reperfusion slopes were calculated: oxyhemoglobin ([HbO2]) decrease rate ([HbO2] slope 1), deoxyhaemoglobin ([HHb]) increase rate ([HHb] slope 1), [HbO2] increase rate ([HbO2] slope 2), and [HHb] increase rate ([HHb] slope 2. Using HbO2 kinetics during the occlusion, mV˙O2 was also calculated to characterize myocytes' metabolic O2 consumption. HbO2 slope 1 value was lower after PBC than before PBC (-0.15 ± 0.08 vs -0.24 ± 0.11 s-1; respectively; P < 0.05) in male participants only. A lower [HHb] slope 1 was also observed after PBC compared to before PBC (0.18 ± 0.10 vs 0.24 ± 0.16 s-1; P < 0.05) with no interaction for sex categories. mV˙O2 was significantly lower after PBC than before (pre values 14.75 ± 3.94 vs 18.47 ± 5.73 μMO2Hb.s-1; respectively; P < 0.01) with no interaction between sex categories. No changes in the calculated slope 2 were observed. These findings suggest that a single session of PBC reduces the muscular metabolic O2 needs at rest; however, it does not alter the vascular ability to provide O2 to the myocytes.

Is it the End of the Ice Age?

The use of the RICE (Rest, Ice, Compression, Elevation) protocol has been the preferred method of treatment for acute musculoskeletal injuries for decades. However, the efficacy of using ice as a recovery strategy following injury in humans remains uncertain, and there is a growing trend recommending against icing following injury. Animal models suggest that while ice can help to accelerate the recovery process, extreme muscle cooling might delay repair and increase muscle scarring. Despite the conflicting evidence, ice should not be dismissed as a potential treatment option. When considering what is known about the injury cascade, the optimal application window for ice is in the immediate acute stage following injury to reduce the proliferation of secondary tissue damage that occurs in the hours after the initial injury. Practitioners should tailor the application of ice based on the injury timeline and repair process, consistent with applications in 20-30 minute intervals within the first 12 hours post-injury. Until the evidence unanimously proves otherwise, the culture of icing injuries should remain a staple in sports medicine.

Continuous cryotherapy vs. traditional cryotherapy after total knee arthroplasty: A systematic review and meta-analysis of randomized controlled trials

Background

Cryotherapy is widely applied to relieve pain and improve functional outcomes after total knee arthroplasty (TKA). New cryotherapy devices have recently been developed to guarantee a fixed temperature for a prolonged time. Therefore, we conducted a systematic review and meta-analysis to compare continuous cryotherapy and traditional cryotherapy (ice bag or gel pack) for patients after TKA.

Methods

This study was conducted according to a predefined protocol registered on PROSPERO. Two independent reviewers performed an electronic database search of PubMed, Embase, Cochrane, Web of Science, Google Scholar, and ClinicalTrials.gov. Dichotomous outcomes were reported as risk difference (RD) with 95% confidence intervals (CIs), and continuous outcomes were reported as mean difference (MD), or standardized mean difference (SMD) with 95% CIs.

Results

Seven trials enrolling a total of 519 patients were included. There were no differences in pain intensity (MD: -0.54, 95% CI: -1.55 to 0.47; P = 0.30), analgesics consumption (MD: -0.37, 95% CI: -1.28 to 0.55; P = 0.43), postoperative range of motion (MD: 0.47, 95% CI: -4.09 to 5.03; P = 0.84), swelling of the knee joint, blood loss, change in hemoglobin, or transfusion rate. Meanwhile, there were no differences in length of hospital stay (MD: -0.77, 95% CI: -1.62 to 0.08; P = 0.07) and adverse events (RD: 0, 95% CI: -0.02 to 0.03; P = 0.74). In addition, continuous cryotherapy leads to extra costs and resources than traditional cryotherapy.

Conclusions

Continuous cryotherapy does not appear to offer significant benefits for TKA when compared with traditional cryotherapy. Based on currently available evidence, traditional cryotherapy is still recommended as continuous cryotherapy is not cost-effective. Further well-designed studies with larger sample sizes are warranted to further confirm these preliminary results. PROSPERO Registration: Identifier [CRD42022308217].

Physical Rehabilitation in Zoological Companion Animals

Animal physical rehabilitation is one of the fast-growing fields in veterinary medicine in recent years. It has become increasingly common in small animal practice and will continue to emerge as an essential aspect of veterinary medicine that plays a vital role in the care of animals with physical impairments or disabilities from surgery, injuries, or diseases.1 This is true now more than ever because of the increasing advances in lifesaving treatments, the increased lifespan of companion animals, and the growth of chronic conditions, of which many are associated with movement disorders. The American Association of Rehabilitation Veterinarians (AARV) defines APR as "the diagnosis and management of patients with painful or functionally limiting conditions, particularly those with injury or illness related to the neurologic and musculoskeletal systems." Rehabilitation not only focuses on recovery after surgical procedures but also on improving the function and quality of life in animals suffering from debilitating diseases such as arthritis or neurologic disorders. The overall goal of APR is to decrease pain, reduce edema, promote tissue healing, restore gait and mobility to its prior activity level, regain strength, prevent further injury, and promote optimal quality of life. Typically, a multimodal approach with pharmaceutical and nonpharmaceutical interventions is used by APR therapists to manage patients during their recovery. The purpose of this article aims to provide knowledge and guidance on physical rehabilitation to help veterinarians in the proper return of their patients with ZCA safely after injury and/or surgery.

Icing after skeletal muscle injury decreases M1 macrophage accumulation and TNF-α expression during the early phase of muscle regeneration in rats

Following skeletal muscle injury, both myogenic and immune cells interact closely during the regenerative process. Although icing is still a common acute treatment for sports-related skeletal muscle injuries, icing after muscle injury has been shown to disrupt macrophage accumulation and impair muscle regeneration in animal models. However, it remains unknown whether icing shortly after injury affects macrophage-related phenomena during the early stages of muscle regeneration. Therefore, we focused on the distribution of M1/M2 macrophages and cytokines expressed predominantly by macrophages during the early stages of muscle regeneration after muscle crush injury. Icing resulted in a decrease, not retardation, in the accumulation of M1 macrophages, but not M2 macrophages, in injured muscles. Consistent with the decrease in M1 macrophage accumulation, icing led to a reduction, instead of delay, in the level of tumor necrosis factor-α (TNF-α) expression. Additionally, at subsequent timepoints, icing decreased the number of myogenic precursor cells in the regenerating area and the size of centrally nucleated regenerating myofibers. Together, our findings suggest that icing after acute muscle damage by crushing disturbs muscle regeneration through hindering tM1 macrophage-related phenomena.

Role of macrophages during skeletal muscle regeneration and hypertrophy-Implications for immunomodulatory strategies

Skeletal muscle is a plastic tissue that regenerates ad integrum after injury and adapts to raise mechanical loading/contractile activity by increasing its mass and/or myofiber size, a phenomenon commonly refers to as skeletal muscle hypertrophy. Both muscle regeneration and hypertrophy rely on the interactions between muscle stem cells and their neighborhood, which include inflammatory cells, and particularly macrophages. This review first summarizes the role of macrophages in muscle regeneration in various animal models of injury and in response to exercise-induced muscle damage in humans. Then, the potential contribution of macrophages to skeletal muscle hypertrophy is discussed on the basis of both animal and human experiments. We also present a brief comparative analysis of the role of macrophages during muscle regeneration versus hypertrophy. Finally, we summarize the current knowledge on the impact of different immunomodulatory strategies, such as heat therapy, cooling, massage, nonsteroidal anti-inflammatory drugs and resolvins, on skeletal muscle regeneration and their potential impact on muscle hypertrophy.

Cryotherapy in Anterior Cruciate Ligamentoplasty Pain: A Scoping Review

Cryotherapy is used in individuals in the postoperative period (PO) of anterior cruciate ligament (ACL) repair, owing to its effects such as increased pain threshold, decreased cellular activity, and vasoconstriction. The aim of this study was to analyze the effect of cryotherapy on pain intensity in the immediate PO of ACL reconstruction. A scoping review was performed in the databases: Cochrane, Embase, Lilacs, LIVIVO, PEDro, PubMed, Scopus, and Web of Science; and gray literature: Google Scholar, CAPES Thesis Database, and Open Grey. PRISMA recommendation was followed. Two blinded reviewers performed the selection of studies: Phase 1-reading of titles and abstracts and Phase 2-Reading of the full texts and disagreements resolved in consensus. The references of 701 studies were identified, 603 from the main databases and 98 from the gray literature. After removal of duplicates, 387 studies were left for Phase 1-reading of titles and abstracts according to eligibility criteria and for Phase 2-28 studies for reading of full texts. Two studies were excluded: one randomized clinical trial and another sandwich study. Finally, 15 studies were included in this review. Cryotherapy is effective in reducing pain intensity because there were reductions in the scores of subjective pain scales in the immediate PO of ACL reconstruction. Cryocompression was shown to be superior to conventional cryotherapy.

Clinical-like cryotherapy in acute knee arthritis of the knee improves inflammation signs, pain, joint swelling, and motor performance in mice

To assess the effects of clinical-like cryotherapy on inflammatory signs (in vivo neutrophil migration, cytokines, and joint inflammation), pain, joint swelling, balance, and motor coordination in mice with knee arthritis. Young C57BL/6 mice were randomly divided into three groups (8 to 10 mice per group): Control group: mice with no intervention; antigen-induced arthritis (AIA) group: mice sensitized and immunized with intra-articular (i.a.) injection of methylated bovine serum albumin (mBSA); and AIA + cryotherapy group: mice sensitized, immunized with i.a. injection of mBSA, and submitted to a clinical-like cryotherapy protocol. After 21 days of sensitization, AIA and AIA + cryotherapy groups received i.a. injection of mBSA (100 μg/joint) to induce joint inflammation, and a clinical-like cryotherapy protocol was applied to AIA + cryotherapy group (crushed ice bag, two cryotherapy sessions of 20 min every two hours). Experimental analysis was conducted in the initial (immediately after i.a. injection of mBSA) and final periods (two hours after the second cryotherapy session). The number of synovial fluid neutrophils, cytokine levels, joint histology, pain, joint swelling, and motor performance were also analyzed. Our results showed that clinical-like cryotherapy in mice with acute knee arthritis reduced inflammatory signs, pain, and joint swelling, and improved balance and motor coordination.

Moderate Treadmill Training Induces Limited Effects on Quadriceps Muscle Hypertrophy in Mice Exposed to Cigarette Smoke Involving Metalloproteinase 2

Background

Long-term cigarette smoke (CS) induces substantive extrapulmonary effects, including musculoskeletal system disorders. Exercise training seems to protect long-term smokers against fiber atrophy in the locomotor muscles. Nevertheless, the extracellular matrix (ECM) changes in response to aerobic training remain largely unknown. Thus, we investigated the effects of moderate treadmill training on aerobic performance, cross-sectional area (CSA), fiber distribution, and metalloproteinase 2 (MMP-2) activity on quadriceps muscle in mice exposed to chronic CS.

Methods

Male mice were randomized into four groups: control or smoke (6 per group) and exercise or exercise+smoke (5 per group). Animals were exposed to 12 commercially filtered cigarettes per day (0.8 mg of nicotine, 10 mg of tar, and 10 mg of CO per cigarette). The CSA, fibers distribution, and MMP-2 activity by zymography were assessed after a period of treadmill training (50% of maximal exercise capacity for 60 min/day, 5 days/week) for 24 weeks.

Results

The CS exposure did not change CSA compared to the control group (p>0.05), but minor fibers in the frequency distribution (<1000 µm²) were observed. Long-term CS exposure attenuated CSA increases in exercise conditions (smoke+exercise vs exercise) while did not impair aerobic performance. Quadriceps CSA increased in mice nonsmoker submitted to aerobic training (p = 0.001). There was higher pro-MMP-2 activity in the smoke+exercise group when compared to the smoke group (p = 0.01). Regarding active MMP-2, the exercise showed higher values when compared to the control group (p = 0.001).

Conclusion

Moderate treadmill training for 24 weeks in mice exposed to CS did not modify CSA, despite inducing higher pro-MMP-2 activity in the quadriceps muscle, suggesting limited effects on ECM remodeling. Our findings may contribute to new insights into molecular mechanisms for CS conditions.

Minor Soft Tissue Injuries may need PEACE in the Acute Phase, but Moderate and Severe Injuries Require CARE

For the past 30 years, conflicting and confusing theories have abounded for the acute-stage treatment of musculoskeletal injuries due to a lack of sufficient, high-quality research that substantiates an ideal approach. The main controversy concerns the use of cryotherapy. While cryotherapy has become established as a vital component of the initial treatment of musculoskeletal injuries as part of the rest, ice, compression and elevation (RICE) approach (Mirkin and Hoffman, 1978), doubts about its efficacy have arisen in recent years. In fact, the latest proposal is to use the protection, elevation, avoid, compression and education (PEACE) approach as acute-stage treatment of musculoskeletal injuries (Dubois and Esculier, 2020). This involves protection and elevation of the injured limb, avoidance of anti-inflammatory drugs and cryotherapy, compression of the injured limb and patient education.

Effect of Cryoablation Treatment on the Protein Expression Profile of Low-Grade Central Chondrosarcoma Identified by LC-ESI-MS/MS

The use of cryoablation/cryosurgery in treating solid tumors has been proven as a unique technique that uses lethal temperatures to destroy the tumors and impart better functions for the affected organs. This novel technique recently demonstrated the best clinical results in chondrosarcoma (CSA) with faster recovery, less recurrence, and metastasis. Due to the resistant nature of CSA to chemo and radiation therapy, cryoablation comes to light as the best alternative approach. Therefore, for the first time, we aimed to compare CSA-untreated with cryoablation treated samples to discover some potential markers that may provide various clues in terms of diagnosis and pathophysiology and may facilitate the development of novel methods to treat sarcoma efficiently. To find the altered proteins among both groups, a mass-based label-free approach was employed and identified a total of 160 significantly altered proteins. Among these, 138 proteins were dysregulated with <1- to -0.1-fold, 18 proteins were up-regulated with >3 folds, and four proteins were similarly expressed in the untreated group compared to the treated. Interestingly, the differential expressions of proteins from the untreated group showed contrast expressions in the treated group. Furthermore, the functional enrichment analysis revealed that most of the identified proteins from this study were associated with various significant pathways such as glycolysis, MAPK activation, PI3K-Akt signaling, extracellular matrix degradation, etc. In addition, two protein expressions, such as fibronectin and annexin-1, were validated by immunoblot analysis. Therefore, this study signifies the most comprehensive discovery of altered protein expressions to date and the first large-scale detection of protein profiles from CSA-cryoablation treated compared to untreated. This work may serve as the basis for future research to open novel treatment options for chondrosarcoma.

The cold truth: the role of cryotherapy in the treatment of injury and recovery from exercise

Cryotherapy is utilized as a physical intervention in the treatment of injury and exercise recovery. Traditionally, ice is used in the treatment of musculoskeletal injury while cold water immersion or whole-body cryotherapy is used for recovery from exercise. In humans, the primary benefit of traditional cryotherapy is reduced pain following injury or soreness following exercise. Cryotherapy-induced reductions in metabolism, inflammation, and tissue damage have been demonstrated in animal models of muscle injury; however, comparable evidence in humans is lacking. This absence is likely due to the inadequate duration of application of traditional cryotherapy modalities. Traditional cryotherapy application must be repeated to overcome this limitation. Recently, the novel application of cooling with 15 °C phase change material (PCM), has been administered for 3-6 h with success following exercise. Although evidence suggests that chronic use of cryotherapy during resistance training blunts the anabolic training effect, recovery using PCM does not compromise acute adaptation. Therefore, following exercise, cryotherapy is indicated when rapid recovery is required between exercise bouts, as opposed to after routine training. Ultimately, the effectiveness of cryotherapy as a recovery modality is dependent upon its ability to maintain a reduction in muscle temperature and on the timing of treatment with respect to when the injury occurred, or the exercise ceased. Therefore, to limit the proliferation of secondary tissue damage that occurs in the hours after an injury or a strenuous exercise bout, it is imperative that cryotherapy be applied in abundance within the first few hours of structural damage.

Effectiveness of cryotherapy on pain intensity, swelling, range of motion, function and recurrence in acute ankle sprain: A systematic review of randomized controlled trials

OBJECTIVE

Investigate effectiveness of cryotherapy on pain intensity, swelling, range of motion, function and recurrence in acute ankle sprain.

METHODS

Searches were conducted on six databases for randomized or quasi-randomized controlled trials (RCTs) evaluating effectiveness of cryotherapy for pain intensity, swelling, range of motion, function and recurrence in acute ankle sprain. Selection of trials, data extraction and methodological quality assessment of included trials were conducted independently by two reviewers with discrepancies resolved by a third reviewer. Estimates were presented as mean differences (MDs) with 95% confidence intervals (CIs). The quality of the evidence was assessed using the Grading of Recommendations Assessment (GRADE) approach.

RESULTS

Two RCTs with high risk of bias were included. Both evaluated the additional effects of cryotherapy, comparing cryotherapy combined with other intervention versus other intervention stand-alone. Uncertain evidence shows that cryotherapy does not enhance effects of other intervention on swelling (MD = 6.0; 95%CI: 0.5 to 12.5), pain intensity (MD = -0.03; 95%CI: 0.34 to 0.28) and range of motion (p > 0.05).

CONCLUSIONS

Current literature lacks evidence supporting the use of cryotherapy on management of acute ankle sprain. There is an urgent call for larger high-quality randomized controlled trials.

Icing after eccentric contraction-induced muscle damage perturbs the disappearance of necrotic muscle fibers and phenotypic dynamics of macrophages in mice

Icing is still one of the most common treatments to acute skeletal muscle damage in sports medicine. However, previous studies using rodents reported the detrimental effect of icing on muscle regeneration following injury. This study aimed to elucidate the critical factors governing the impairment of muscle regeneration by icing with a murine model of eccentric contraction-induced muscle damage by electrical stimulation. Because of icing after muscle injury, the infiltration of polynuclear and mononuclear cells into necrotic muscle fibers was retarded and attenuated, leading to the persistent presence of necrotic cellular debris. These phenomena coincided with the delayed emergence and sustained accumulation of Pax7⁺ myogenic cells within the regenerating area. In addition, due to icing, delayed and/or sustained infiltration of M1 macrophages was noted in accordance with the perturbed expression patterns of inflammation-related factors, including tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). The key myogenic regulatory factors (i.e., MyoD and myogenin) involved in the activation/proliferation and differentiation of myogenic precursor cells were not altered by icing during the regenerative process. A detailed analysis of regenerating myofibers by size distribution at day 14 after muscle damage showed that the ratio of small regenerating fibers to total regenerating fibers was higher in icing-treated animals than in untreated animals. These findings suggest that icing following muscle damage blunts the efficiency of muscle regeneration by perturbing the removal of necrotic myofibers and phenotypic dynamics of macrophages rather than affecting myogenic factors.NEW & NOTEWORTHY Icing blunted the muscle regeneration by perturbing the infiltration of polynuclear and mononuclear cells into necrotic myofibers and the phenotypic dynamics of macrophages rather than affecting the myogenic regulatory factors. Because of icing, the disappearance of necrotic muscle debris was retarded, coinciding with the delayed emergence and sustained accumulation of Pax7⁺ cells within the regenerating area. The expression patterns of TNF-α and IL-10 were altered by icing consistent with the perturbation of the macrophage phenotype.

Shall we use cryotherapy in the treatment in surgical procedures, in acute pain or injury, or in long term pain or dysfunction? - A systematic review

PURPOSE

This review aimed to evaluate the certainty of evidence for the use of cryotherapy in patients with musculoskeletal disorders.

METHODS

PubMed, Embase, Cochrane Library and AMED were searched from January 2000 to January 2018 (update June 2019) for systematic reviews (SRs) and randomized controlled trials (RCTs) reporting outcomes on pain, swelling, range of motion (ROM), function, blood loss, analgesic use, patient satisfaction and adverse advents. The papers were categorised into: surgical procedures, acute pain or injury and long-term pain or dysfunction. Methodological quality and risk of bias were assessed using the AMSTAR and the Swedish Health Technology Assessment instruments. Level of certainty of evidence was synthesized using GRADE.

STUDY SELECTION

Eight SRs and 50 RCTs from a total of 6027 (+839) were included. In total 34 studies evaluated cryotherapy in surgical procedures, twelve evaluated cryotherapy use in acute pain or injury and twelve studies evaluated cryotherapy in long-term pain and dysfunction.

RESULTS

The certainty of evidence is moderate (GRADE III) after surgical procedures to reduce pain, improve ROM, for patient satisfaction and few adverse events are reported. Cryotherapy in acute pain and injury or long-term pain and dysfunction show positive effects but have a higher number of outcomes with low certainty of evidence (GRADE II).

CONCLUSION

Cryotherapy may safely be used in musculoskeletal injuries and dysfunctions. It is well tolerated by patients. More advanced forms of cryotherapy may accentuate the effect. Future research is needed where timing, temperature for cooling, dose (time) and frequency are evaluated.

Effects of cryotherapy on the regeneration process and muscular mechanical properties after lacerative injury model

Cryotherapy is a therapeutic modality widely used for the treatment of muscle injuries to control pain and inflammatory processes. This study aimed to investigate the effects of cryotherapy on the inflammatory and oxidative stress parameters and mechanical properties of, and pain in, the skeletal muscles of rats with lacerative muscle injury. The rats were anesthetized with 4% isoflurane and subjected to gastrocnemius muscle laceration injury. After injury, all animals in the intervention groups received cryotherapy treatment for 20 minutes using plastic bags containing crushed ice. The protocol comprised three daily applications at 3-hour intervals on the day of injury, with reapplication 24 hours later. Seventy-two male Wistar rats were divided into three groups: sham, muscle injury (MI), and MI + cryotherapy (MI + cryo). Muscle mechanical properties were analyzed by mechanical tensile testing on day 7 after injury. The MI + cryo group showed reduced TNF-α, IFN-γ, and IL1β levels; elevated IL4, IL6, and IL10 levels; reduced oxidant production and carbonyl levels; and elevated sulfhydryl contents. Animals that underwent tissue cooling showed superoxide dismutase activity and glutathione levels close to those of the animals in the sham group. The MI and MI + cryo groups showed reduced values of the evaluated mechanical properties and lower mechanical thresholds compared to those of the animals from the sham group. Our results demonstrated that the proposed cryotherapy protocol reduced the inflammatory process and controlled oxidative stress but did not reverse the changes in the mechanical properties of muscle tissues or provide analgesic effects within the time frame analyzed.

Effects of Physical Agents on Muscle Healing with a Focus on Animal Model Research

Skeletal muscle injury is caused by a variety of events, such as muscle laceration, contusions, or strain. Muscle fibers respond to minor damage with immediate repair mechanisms that reseal the cell membrane. On the other hand, repair of irreversibly damaged fibers is achieved by activation of muscle precursor cells. Muscle repair is not always perfect, especially after severe damage, and can lead to excessive fibroblast proliferation that results in the formation of scar tissue within muscle fibers. Remaining scar tissue can impair joint movement, reduce muscular strength, and inhibit exercise ability; therefore, to restore muscle function, minimizing the extent of injury and promoting muscle regeneration are necessary. Various physical agents, such as cold, thermal, electrical stimulation, and low-intensity pulsed ultrasound therapy, have been reported as treatments for muscle healing. Although approaches based on the muscle regeneration process have been under development, the most efficacious physiological treatment for muscle injury remains unclear. In this review, the influence of these physical agents on muscle injury is described with a focus on research using animal models.

Effects of Cryotherapy Applied at Different Temperatures on Inflammatory Pain During the Acute Phase of Arthritis in Rats

OBJECTIVE

The biological mechanisms of cryotherapy for managing acute pain remain unclear. Additionally, it is unknown whether the effectiveness of cryotherapy depends on the applied temperature. This study aimed to clarify the biological effects of cryotherapy and to examine the therapeutic effects of cryotherapy applied at different temperatures in rats.

METHODS

This was an experimental study using a rat knee joint arthritis model. Thirty-five Wistar rats were randomly divided into arthritis (AR), arthritis with 5°C cryotherapy (CR-5), arthritis with 10°C cryotherapy (CR-10), and sham-arthritis control (CON) groups. Arthritis was induced by injecting a mixture of kaolin/carrageenan into the right knee joint. Cryotherapy was applied for 7 days starting the day after injection by immersing the right knee joint in 5°C or 10°C water. Joint transverse diameter, pressure pain threshold, and pain-related behaviors were assessed for 7 days. The number of CD68-positive cells in the knee joint and the expression of calcitonin gene-related peptide in the spinal dorsal horn 8 days after injection were analyzed by immunohistochemical staining.

RESULTS

Improvements in transverse diameter, pressure pain threshold, and pain-related behaviors were observed in the CR-5 and CR-10 groups on the 3rd day compared with the AR group. The number of CD68-positive cells and the expression of calcitonin gene-related peptide in the CR-5 and CR-10 groups were significantly decreased compared with the AR group. There were no significant differences in all results between the CR-5 and CR-10 groups.

CONCLUSIONS

Cryotherapy can ameliorate inflammatory pain through reduction of synovium and central sensitization. Additionally, the effects of cryotherapy lower than 10°C are observed independent of applied temperature.

IMPACT

Cryotherapy may be beneficial as a physical therapy modality for pain and swelling management in the acute phase of inflammation. Translational human study is needed to determine the effective cryotherapy temperature for the inflammatory pain.

Orthopaedic Application of Cryotherapy: A Comprehensive Review of the History, Basic Science, Methods, and Clinical Effectiveness

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Cold therapy, also known as cryotherapy, includes the use of bagged ice, ice packs, compressive cryotherapy devices, or whole-body cryotherapy chambers. Cryotherapy is commonly used in postoperative care for both arthroscopic and open orthopaedic procedures.

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Cryotherapy is associated with an analgesic effect caused by microvasculature alterations that decrease the production of inflammatory mediators, decrease local edema, disrupt the overall inflammatory response, and reduce nerve conduction velocity.

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Postoperative cryotherapy using bagged ice, ice packs, or continuous cryotherapy devices reduced visual analog scale pain scores and analgesic consumption in approximately half of research studies in which these outcomes were compared with no cryotherapy (11 [44%] of 25 studies on pain and 11 [48%] of 23 studies on opioids). However, an effect was less frequently reported for increasing range of motion (3 [19%] of 16) or decreasing swelling (2 [22%] of 9).

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Continuous cryotherapy devices demonstrated the best outcome in orthopaedic patients after knee arthroscopy procedures, compared with all other procedures and body locations, in terms of showing a significant reduction in pain, swelling, and analgesic consumption and increase in range of motion, compared with bagged ice or ice packs.

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There is no consensus as to whether the use of continuous cryotherapy devices leads to superior outcomes when compared with treatment with bagged ice or ice packs. However, complications from cryotherapy, including skin irritation, frostbite, perniosis, and peripheral nerve injuries, can be avoided through patient education and reducing the duration of application.

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Future Level-I or II studies are needed to compare both the clinical and cost benefits of continuous cryotherapy devices to bagged ice or ice pack treatment before continuous cryotherapy devices can be recommended as a standard of care in orthopaedic surgery following injury or surgery.

A Tangled Threesome: Circadian Rhythm, Body Temperature Variations, and the Immune System

Simple Summary

In mammals, including humans, the body temperature displays a circadian rhythm and is maintained within a narrow range to facilitate the optimal functioning of physiological processes. Body temperature increases during the daytime and decreases during the nighttime thus influencing the expression of the molecular clock and the clock-control genes such as immune genes. An increase in body temperature (daytime, or fever) also prepares the organism to fight aggression by promoting the activation, function, and delivery of immune cells. Many factors may affect body temperature level and rhythm, including environment, age, hormones, or treatment. The disruption of the body temperature is associated with many kinds of diseases and their severity, thus supporting the assumed association between body temperature rhythm and immune functions. Recent studies using complex analysis suggest that circadian rhythm may change in all aspects (level, period, amplitude) and may be predictive of good or poor outcomes. The monitoring of body temperature is an easy tool to predict outcomes and maybe guide future studies in chronotherapy.

Abstract

The circadian rhythm of the body temperature (CRBT) is a marker of the central biological clock that results from multiple complex biological processes. In mammals, including humans, the body temperature displays a strict circadian rhythm and has to be maintained within a narrow range to allow optimal physiological functions. There is nowadays growing evidence on the role of the temperature circadian rhythm on the expression of the molecular clock. The CRBT likely participates in the phase coordination of circadian timekeepers in peripheral tissues, thus guaranteeing the proper functioning of the immune system. The disruption of the CRBT, such as fever, has been repeatedly described in diseases and likely reflects a physiological process to activate the molecular clock and trigger the immune response. On the other hand, temperature circadian disruption has also been described as associated with disease severity and thus may mirror or contribute to immune dysfunction. The present review aims to characterize the potential implication of the temperature circadian rhythm on the immune response, from molecular pathways to diseases. The origin of CRBT and physiological changes in body temperature will be mentioned. We further review the immune biological effects of temperature rhythmicity in hosts, vectors, and pathogens. Finally, we discuss the relationship between circadian disruption of the body temperature and diseases and highlight the emerging evidence that CRBT monitoring would be an easy tool to predict outcomes and guide future studies in chronotherapy.

Extracellular matrix at the muscle - tendon interface: functional roles, techniques to explore and implications for regenerative medicine

The muscle-tendon interface is an anatomically specialized region that is involved in the efficient transmission of force from muscle to tendon. Due to constant exposure to loading, the interface is susceptible to injury. Current treatment methods do not meet the socioeconomic demands of reduced recovery time without compromising the risk of reinjury, requiring the need for developing alternative strategies. The extracellular matrix (ECM) present in muscle, tendon, and at the interface of these tissues consists of unique molecules that play significant roles in homeostasis and repair. Better, understanding the function of the ECM during development, injury, and aging has the potential to unearth critical missing information that is essential for accelerating the repair at the muscle-tendon interface. Recently, advanced techniques have emerged to explore the ECM for identifying specific roles in musculoskeletal biology. Simultaneously, there is a tremendous increase in the scope for regenerative medicine strategies to address the current clinical deficiencies. Advancements in ECM research can be coupled with the latest regenerative medicine techniques to develop next generation therapies that harness ECM for treating defects at the muscle-tendon interface. The current work provides a comprehensive review on the role of muscle and tendon ECM to provide insights about the role of ECM in the muscle-tendon interface and discusses the latest research techniques to explore the ECM to gathered information for developing regenerative medicine strategies.

Multiple Cryotherapy Attenuates Oxi-Inflammatory Response Following Skeletal Muscle Injury

The oxi-inflammatory response is part of the natural process mobilizing leukocytes and satellite cells that contribute to clearance and regeneration of damaged muscle tissue. In sports medicine, a number of post-injury recovery strategies, such as whole-body cryotherapy (WBC), are used to improve skeletal muscle regeneration often without scientific evidence of their benefits. The study was designed to assess the impact of WBC on circulating mediators of skeletal muscle regeneration. Twenty elite athletes were randomized to WBC group (3-min exposure to −120 °C, twice a day for 7 days) and control group. Blood samples were collected before the first WBC session and 1 day after the last cryotherapy exposure. WBC did not affect the indirect markers of muscle damage but significantly reduced the generation of reactive oxygen and nitrogen species (H₂O₂ and NO) as well as the concentrations of serum interleukin 1β (IL-1β) and C-reactive protein (CRP). The changes in circulating growth factors, hepatocyte growth factor (HGF), insulin-like growth factor (IGF-1), platelet-derived growth factor (PDGF^BB), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF), were also reduced by WBC exposure. The study demonstrated that WBC attenuates the cascade of injury–repair–regeneration of skeletal muscles whereby it may delay skeletal muscle regeneration.

Don't Lose Your Cool With Cryotherapy: The Application of Phase Change Material for Prolonged Cooling in Athletic Recovery and Beyond

Strenuous exercise can result in muscle damage in both recreational and elite athletes, and is accompanied by strength loss, and increases in soreness, oxidative stress, and inflammation. If the aforementioned signs and symptoms associated with exercise-induced muscle damage are excessive or unabated, the recovery process becomes prolonged and can result in performance decrements; consequently, there has been a great deal of research focussing on accelerating recovery following exercise. A popular recovery modality is cryotherapy which results in a reduction of tissue temperature by the withdrawal of heat from the body. Cryotherapy is advantageous because of its ability to reduce tissue temperature at the site of muscle damage. However, there are logistical limitations to traditional cryotherapy modalities, such as cold-water immersion or whole-body cryotherapy, because they are limited by the duration for which they can be administered in a single dose. Phase change material (PCM) at a temperature of 15°C can deliver a single dose of cooling for a prolonged duration in a practical, efficacious, and safe way; hence overcoming the limitations of traditional cryotherapy modalities. Recently, 15°C PCM has been locally administered following isolated eccentric exercise, a soccer match, and baseball pitching, for durations of 3-6 h with no adverse effects. These data showed that using 15°C PCM to prolong the duration of cooling successfully reduced strength loss and soreness following exercise. Extending the positive effects associated with cryotherapy by prolonging the duration of cooling can enhance recovery following exercise and give athletes a competitive advantage.

Local cooling for relieving pain from perineal trauma sustained during childbirth

BACKGROUND

Perineal trauma is common during childbirth and may be painful. Contemporary maternity practice includes offering women numerous forms of pain relief, including the local application of cooling treatments. This Cochrane Review is an update of a review last updated in 2012.

OBJECTIVES

To evaluate the effectiveness of localised cooling treatments compared with no treatment, placebo, or other cooling treatments applied to the perineum for pain relief following perineal trauma sustained during childbirth.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 October 2019) and reference lists of retrieved studies.

SELECTION CRITERIA

Published and unpublished randomised and quasi-randomised trials (RCTs) that compared a localised cooling treatment applied to the perineum with no treatment, placebo, or another cooling treatment applied to relieve pain related to perineal trauma sustained during childbirth.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were double checked for accuracy. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 10 RCTs that enrolled 1233 women randomised to the use of one cooling treatment (ice, cold gel pad, cooling plus compression, cooling plus compression plus (being) horizontal) compared with another cooling treatment, no treatment, or placebo (water pack, compression). The included trials were at low or uncertain risk of bias overall, with the exception that the inability to blind participants and personnel to group allocation meant that we rated all trials at unclear or high risk for this domain. We undertook a number of comparisons to evaluate the different treatments. Cooling treatment (ice pack or cold gel pad) versus no treatment There was limited very low-certainty evidence that cooling treatment may reduce women's self-reported perineal pain within four to six hours (mean difference (MD) -4.46, 95% confidence interval (CI) -5.07 to -3.85 on a 10-point scale; 1 study, 100 participants) or between 24 and 48 hours of giving birth (risk ratio (RR) 0.73, 95% CI 0.57 to 0.94; 1 study, 316 participants). The evidence is very uncertain about the various measures of wound healing, for example, wound edges gaping when inspected five days after giving birth (RR 2.56, 95% CI 0.58 to 11.33; 1 study, 315 participants). Women generally rated their satisfaction with perineal care similarly following cooling or no treatment. The potential exception was that there may be a trivially lower mean difference of -0.1 on a five-point scale of psychospiritual comfort with cooling treatment, that is unlikely to be of clinical importance. Cooling treatment (cold gel pad) + compression versus placebo (gel pad + compression) There was limited low-certainty evidence that there may be a trivial MD of -0.43 in pain on a 10-point scale at 24 to 48 hours after giving birth (95% CI -0.73 to -0.13; 1 study, 250 participants) when a cooling treatment plus compression from a well-secured perineal pad was compared with the placebo. Levels of perineal oedema may be similar for the two groups (low-certainty evidence) and perineal bruising was not observed. There was low-certainty evidence that women may rate their satisfaction as being slightly higher with perineal care in the cold gel pad and compression group (MD 0.88, 95% CI 0.38 to 1.38; 1 trial, 250 participants). Cooling treatment (ice pack) versus placebo (water pack) One study reported that no women reported pain after using an ice pack or a water pack when asked within 24 hours of giving birth. There was low-certainty evidence that oedema may be similar for the two groups when assessed at four to six hours (RR 0.96, 95% CI 0.50 to 1.86; 1 study, 63 participants) or within 24 hours of giving birth (RR 0.36, 95% CI 0.08 to 1.59). No women were observed to have perineal bruising at these times. The trialists reported that no women in either group experienced any adverse effects on wound healing. There was very low-certainty evidence that women may rate their views and experiences with the treatments similarly (for example, satisfied with treatment: RR 0.91, 95% CI 0.77 to 1.08; 63 participants). Cooling treatment (ice pack) versus cooling treatment (cold gel pad) The evidence is very uncertain about the effects of using ice packs or cold gel pads on women's self-rated perineal pain, on perineal bruising, or on perineal oedema at four to six hours or within 24 hours of giving birth. Perineal oedema may persist 24 to 48 hours after giving birth in women using the ice packs (RR 1.69, 95% CI 1.03 to 2.7; 2 trials, 264 participants; very low-certainty). The risk of gaping wound edges five days after giving birth may be decreased in women who had used ice packs (RR 0.22, 95% CI 0.05 to 1.01; 215 participants; very low-certainty). However, this did not appear to persist to day 10 (RR 3.06, 95% CI 0.63 to 14.81; 214 participants). Women may rate their opinion of treatment less favourably following the use of ice packs five days after giving birth (RR 0.33, 95% CI 0.17 to 0.68; 1 study, 49 participants) and when assessed on day 10 (RR 0.82, 95% CI 0.73 to 0.92; 1 study, 208 participants), both very low-certainty.

AUTHORS' CONCLUSIONS

There is limited very low-certainty evidence that may support the use of cooling treatments, in the form or ice packs or cold gel pads, for the relief of perineal pain in the first two days following childbirth. It is likely that concurrent use of several treatments is required to adequately address this issue, including prescription and non-prescription analgesia. Studies included in this review involved the use of cooling treatments for 10 to 20 minutes, and although no adverse effects were noted, these findings came from studies of relatively small numbers of women, or were not reported at all. The continued lack of high-certainty evidence of the benefits of cooling treatments should be viewed with caution, and further well-designed trials should be conducted.

Efecto de la crioterapia en la articulación tibiotarsiana en el área de sección transversa del tibial anterior y el sóleo en ratas

Introducción. La crioterapia se usa para tratar la inflamación articular aguda, sin embargo su efecto sobre el músculo relacionado con la articulación inflamada aún no ha sido estudiado.Objetivo. Evaluar el efecto de la crioterapia sobre la articulación tibiotarsiana en el área de sección transversa (AST) de los músculos tibial anterior (TA) y sóleo en ratas con inflamación articular aguda.Materiales y métodos. Estudio experimental realizado en 32 ratas Wistar que fueron asignadas aleatoriamente a cuatro grupos: Control, Inflamación, Crioterapia-A y Crioterapia-B. El AST de las fibras de los músculos se midió 72 horas después de haberse iniciado el experimento.Resultados. En el tibial anterior hubo una reducción significativa del AST de las fibras musculares en los grupos Inflamación y Crioterapia-B en comparación con el grupo Control, mientras que en el grupo Crioterapia-A no se observó una reducción significativa en dicha área al compararlo con el Control. En el caso del músculo sóleo, se observó una reducción significativa del área en todos los grupos experimentales.Conclusión. El uso de crioterapia una vez al día por tres días atenúa el efecto atrófico de la inflamación articular aguda sobre el músculo TA, lo que confirma su importancia en el control del efecto deletéreo de la inflamación aguda sobre músculos de contracción rápida.

Rol de los agentes físicos en la rehabilitación vocal: una revisión de la literatura

Los agentes físicos son elementos naturales o artificiales que se aplican para el tratamiento de determinados síntomas o patologías. En la rehabilitación vocal su estudio es un área emergente, donde las revisiones sistemáticas y los meta-análisis son escasos. Esto, muchas veces, dificulta la toma de decisiones y la correcta elección por parte del clínico.  El objetivo de este trabajo fue analizar el rol de los agentes físicos en la rehabilitación vocal. Se realizó una revisión de la literatura a través de la búsqueda de artículos en las bases de datos PubMed, EBSCOHost y Scielo. Se establecieron criterios de elegibilidad según tipo, año y características de los estudios. Se evaluaron 603 artículos, de los cuales, luego del análisis de su título, abstract y del cumplimiento de los criterios de elegibilidad, se seleccionaron 16. Se entregan resultados en base a la cantidad de participantes, nivel de evidencia, tipo y configuración del agente físico, procedimientos e instrumentos de evaluación y beneficios obtenidos. Los agentes físicos de mayor utilización en la clínica vocal son la electroterapia (TENS y NMES) y la laserterapia. En general, estos actúan como coadyuvantes en la terapia vocal. La TENS reduce el dolor, la tensión laríngea y la percepción de voz apretada durante la fonación. La NMES beneficia la activación neuromuscular de las cuerdas vocales y el uso de láser permite la recuperación de los tejidos laríngeos posterior a tareas de sobrecarga.

The Effects of Cold Water Immersion and Active Recovery on Molecular Factors That Regulate Growth and Remodeling of Skeletal Muscle After Resistance Exercise

Regular postexercise cooling attenuates muscle hypertrophy, yet its effects on the key molecular factors that regulate muscle growth and remodeling are not well characterized. In the present study, nine men completed two sessions of single-leg resistance exercise on separate days. On 1 day, they sat in cold water (10°C) up to their waist for 10 min after exercise. On the other day, they exercised at a low intensity for 10 min after exercise. Muscle biopsies were collected from the exercised leg before, 2, 24, and 48 h after exercise in both trials. These muscle samples were analyzed to evaluate changes in genes and proteins involved in muscle growth and remodeling. Muscle-specific RING finger 1 mRNA increased at 2 h after both trials (P < 0.05), while insulin-like growth factor (IGF)-1 Ec, IGF-1 receptor, growth arrest and DNA damage-inducible protein 45, collagen type I alpha chain A, collagen type III alpha chain 1, laminin and tissue inhibitor of metallopeptidase 1 mRNA increased 24−48 h after both trials (P < 0.05). By contrast, atrogin-1 mRNA decreased at all time points after both trials (P < 0.05). Protein expression of tenascin C increased 2 h after the active recovery trial (P < 0.05), whereas FoxO3a protein expression decreased after both trials (P < 0.05). Myostatin mRNA and ubiquitin protein expression did not change after either trial. These responses were not significantly different between the trials. The present findings suggest that regular cold water immersion attenuates muscle hypertrophy independently of changes in factors that regulate myogenesis, proteolysis and extracellular matrix remodeling in muscle after exercise.

Ice therapy: cool, current and complicated

This is the fourth Capsule review article provided by the WSAVA Global Pain Council and which discusses the use of ice or cold therapy as a non-pharmacologic modality for pain control in small animal practice. The physiological effects of cold therapy on tissues, receptors and ion channels are discussed; as well as indications, recommendations for, and limitations of use.

Distinct effects of thermal treatments after lengthening contraction on mechanical hyperalgesia and exercise-induced physiological changes in rat muscle

Delayed-onset muscle soreness (DOMS) is a common but displeasing event induced by excessive muscle use or unaccustomed exercise and characterized by tenderness and movement-related pain in the exercised muscle. Thermal therapies, either icing or heating applied to muscles immediately after exercise, have been used as therapeutic interventions for DOMS. However, the mechanisms of their analgesic effects, and physiological and metabolic changes in the muscle during thermal therapy, remain unclear. In the present study, we investigated the effects of both thermal treatments on mechanical hyperalgesia of DOMS and physiological and muscle metabolite changes using the rat DOMS model induced by lengthening contraction (LC) to the gastrocnemius muscle. Heating treatment just after LC induced analgesic effects, while rats with icing treatment showed mechanical hyperalgesia similar to that of the LC group. Furthermore, increased physiological responses (e.g., muscle temperature and blood flow) following the LC were significantly kept high only in the rats with heating treatment. In addition, heating treatment increased metabolites involved in the improvement of blood flow and oxidative metabolisms in the exercised muscle. The results indicated that heating treatment just after LC has analgesic effects on DOMS, which might be mediated partly through the improvement of muscle oxidative metabolisms by changes in metabolites and elevated physiological responses.NEW & NOTEWORTHY Physiological effects of thermal therapy in the muscle and its mechanisms of analgesic effects remain unclear. The results indicated that heating, but not icing, treatment just after lengthening contractions induced analgesic effects in the rat muscle. Increases in hemodynamics, muscle temperature, and metabolites such as nicotinamide were more prominent in heating treatment, consistent with improvement of muscle oxidative metabolisms, which might reduce chemical factors to induce mechanical hyperalgesia.

Clinical-like cryotherapy improves footprint patterns and reduces synovial inflammation in a rat model of post-traumatic knee osteoarthritis

Cryotherapy is a non-pharmacological treatment commonly used to control inflammation and improve function after acute traumas. However, there are no definitive findings about its effects on chronic joint diseases such as knee osteoarthritis (KOA). The aim of this study was to investigate the effects of clinical-like cryotherapy on functional impairment and synovial inflammation in a rat model of KOA generated by anterior cruciate ligament transection (ACLT). Thirty-two male Wistar rats were randomly divided into four groups (n = 8/group): Control, KOA, KOA + Cryotherapy and KOA + Placebo. The last two groups were submitted to the relevant interventions twice a day for five days (61 to 65), with each session lasting 20 min. Gait test, skin temperature, thermal response threshold and joint swelling were assessed in all groups before ACLT surgery, and pre (60th day) and post (66th day) intervention protocols. On day 66, the animals were euthanized and exsanguinated to remove the synovial membrane for histopathological examination and synovial fluid to determine the leukocyte count and cytokine concentration. After the intervention period (66th day), footprint area only increased in the KOA + Cryotherapy group (P = 0.004; 14%) when compared to KOA and KOA + Placebo, but did not differ from controls. Cryotherapy lowered the synovial fluid leukocyte count (P < 0.0001; ≥95.0%) and cytokine concentration (P < 0.0001; ≥55%) when compared to the KOA and Placebo groups. Synovial score and synovial fibrosis did not differ in the KOA groups. In conclusion, footprint patterns improved in rats with ACLT-induced KOA as a result of clinical-like cryotherapy, which also lowered the synovial fluid leukocyte count and inflammatory cytokine concentration in these rats.

Calcaneal Tendon Plasticity Following Gastrocnemius Muscle Injury in Rat

Cross-talk between skeletal muscle and tendon is important for tissue homeostasis. Whereas the skeletal muscle response to tendon injury has been well-studied, to the best of our knowledge the tendon response to skeletal muscle injury has been neglected. Thus, we investigated calcaneal tendon extracellular matrix (ECM) remodeling after gastrocnemius muscle injury using a rat model. Wistar rats were randomly divided into four groups: control group (C; animals that were not exposed to muscle injury) and harvested at different time points post gastrocnemius muscle injury (3, 14, and 28 days) for gene expression, morphological, and biomechanical analyses. At 3 days post injury, we observed mRNA-level dysregulation of signaling pathways associated with collagen I accompanied with disrupted biomechanical properties. At 14 days post injury, we found reduced collagen content histologically accompanied by invasion of blood vessels into the tendon proper and an abundance of peritendinous sheath cells. Finally, at 28 days post injury, there were signs of recovery at the gene expression level including upregulation of transcription factors related to ECM synthesis, remodeling, and repair. At this time point, tendons also presented with increased peritendinous sheath cells, decreased adipose cells, higher Young's modulus, and lower strain to failure compared to the uninjured controls and all post injury time points. In summary, we demonstrate that the calcaneal tendon undergoes extensive ECM remodeling in response to gastrocnemius muscle injury leading to altered functional properties in a rat model. Tendon plasticity in response to skeletal muscle injury merits further investigation to understand its physiological relevance and potential clinical implications.

Non-invasive Assessment of Changes in Muscle Injury by Ultrasound Shear Wave Elastography: An Experimental Study in Contusion Model

The present study investigated the potential of ultrasound shear wave elastography (SWE) in assessment of muscle stiffness in muscle injury. SWE was performed on the injured muscle in 30 New Zealand rabbits that were randomly assigned to three groups: the contusion group, which was not treated with an efficient therapeutic strategy after muscle injury; the treatment group, which was treated with a therapeutic scheme after muscle injury; and the healthy group, which was not injured and served as a control. Both the mean Young's modulus (E_mean) and the maximum Young's modulus (E_max) were obtained pre-injury and 0.5, 1, 3, 5, 7, 14 and 28 d post-injury. At these time points, a rabbit in each group was randomly selected for biopsy for histopathological observation as well as comparison with Young's modulus. Eventually, all muscle tissues were collected for histologic analysis of collagen fiber formation. The contusion group had the highest Young's modulus, followed by the treatment group and then the healthy group (p < 0.05). In both the contusion and treatment groups, E_mean and E_max gradually increased within 1-3 d after injury, followed by a gradual decrease. Compared with the healthy group, histopathologic analysis of the contusion and treatment groups revealed the myofibril destruction process, inflammatory reaction and myofibril regeneration. The amount of collagen fibers in the contusion group was maximal compared with the treated and healthy groups (p = 0.001 and p < 0.001, respectively). There were more collagen fibers in the treatment group than in the healthy group (p = 0.003). The abundance of collagen fibers was positively correlated with the value of Young's modulus (E_mean: r = 0.706, p < 0.001; E_max: r = 0.761, p < 0.001). Thus, SWE can be used to detect pathologic changes in injured muscle and to monitor therapeutic effects.

Thermoelectric Heat Patch for Clinical and Self-Management: Melanoma Excision Wound Care

Thermotherapy is considered to have potential beneficial effects when applied to wounds. Of particular relevance to this research are wounds that have dropped in temperature due to regional anaesthesia. This study is aimed at developing a normothermic system comprising of a heat patch controlled by external hardware. The study is divided into three parts: (i) the analyses of the skin temperature that form the foundation of the system; (ii) the development of an efficient wearable heat patch incorporating thermoelectric elements to electrical and thermal conductive textiles; and (iii) the hardware development to control the current flow to the thermoelectric elements thus managing the temperature of the heat patch and conserving current. It was observed that a distance of 3 cm between the thermoelectric elements provides ideal heat distribution relative to the surface area. The system allowed for an 80% reduction in current, while maintaining the temperature of the heat patch at the required thermophysiological skin temperature. Future studies will include development of a temperature sensor identifying the real-time temperature of the wound; and circuitry for switching the polarity of the thermoelectric elements. The cooling capabilities of the thermoelectric elements can be applied to wounds that have increased in temperature.

Multiple Cold-Water Immersions Attenuate Muscle Damage but not Alter Systemic Inflammation and Muscle Function Recovery: A Parallel Randomized Controlled Trial

The aim of this study was to investigate the effects of multiple cold-water immersions (CWIs) on muscle function, markers of muscle damage, systemic inflammation and ECM degradation following exercise-induced muscle damage (EIMD). Thirty physically active males were randomly assigned to either a control (n = 15) or cold-water immersion (CWI) group (n = 15). The CWI group performed one immersion (10 °C for 20 min) at post-exercise and every 24 h for the following 72 h, while the control group remained in a seated position during these corresponding periods. Muscle strength, vertical jump height, muscle thickness, delayed-onset muscle soreness (DOMS), systemic creatine kinase (CK), C-reactive protein (CRP), inflammatory cytokines and matrix metalloproteinase-2 (MMP-2) activity were assessed at Pre, Post, 24, 48, 72, 96 and 168 h following EIMD. No significant time × group interaction was obtained for muscle strength, vertical jump height recovery and MMP-2 activity (p > 0.05). At 24 h, muscle thickness from the CWI group returned to baseline and was lower than the control (p = 0.04). DOMS returned to baseline at 168 h for the CWI group (p = 0.109) but not for the control (p = 0.008). At 168 h, CK showed a time-group difference with a greater peak for the control group (p = 0.016). In conclusion, multiple CWIs attenuated muscle damage, but not altered systemic inflammation and muscle function recovery.

Regulation of extracellular matrix elements and sarcomerogenesis in response to different periods of passive stretching in the soleus muscle of rats

Stretching is a common method used to prevent muscle shortening and improve limited mobility. However, the effect of different time periods on stretching-induced adaptation of the extracellular matrix and its regulatory elements have yet to be investigated. We aimed to evaluate the expression of fibrillar collagens, sarcomerogenesis, metalloproteinase (MMP) activity and gene expression of the extracellular matrix (ECM) regulators in the soleus (SOL) muscle of rats submitted to different stretching periods. The soleus muscles were submitted to 10 sets of passive stretching over 10 (St 10d) or 15 days (St 15d) (1 min per set, with 30 seconds' rest between sets). Sarcomerogenesis, muscle cross-sectional area (CSA), and MMP activity and mRNA levels in collagen (type I, III and IV), connective tissue growth factor (CTGF), growth factor-beta (TGF-β), and lysyl oxidase (LOX) were analyzed. Passive stretching over both time periods mitigated COL-I deposition in the SOL muscle of rats. Paradoxically, 10 days of passive stretching induced COL-I and COL-III synthesis, with concomitant upregulation of TGF-β1 and CTGF at a transcriptional level. These responses may be associated with lower LOX mRNA levels in SOL muscles submitted to 10 passive stretching sessions. Moreover, sarcomerogenesis was observed after 15 days of stretching, suggesting that stretching-induced muscle adaptations are time-dependent responses.

Cold Water Mediates Greater Reductions in Limb Blood Flow than Whole Body Cryotherapy

PURPOSE

Cold-water immersion (CWI) and whole body cryotherapy (WBC) are widely used recovery methods in an attempt to limit exercise-induced muscle damage, soreness, and functional deficits after strenuous exercise. The aim of this study was to compare the effects of ecologically valid CWI and WBC protocols on postexercise lower limb thermoregulatory, femoral artery, and cutaneous blood flow responses.

METHODS

Ten males completed a continuous cycle exercise protocol at 70% maximal oxygen uptake until a rectal temperature of 38°C was attained. Participants were then exposed to lower-body CWI (8°C) for 10 min, or WBC (-110°C) for 2 min, in a randomized crossover design. Rectal and thigh skin, deep, and superficial muscle temperatures, thigh, and calf skin blood flow (laser Doppler flowmetry), superficial femoral artery blood flow (duplex ultrasound), and arterial blood pressure were measured before, and for 40 min post, cooling interventions.

RESULTS

Greater reductions in thigh skin (CWI, -5.9°C ± 1.8°C; WBC, 0.2°C ± 0.5°C; P < 0.001) and superficial (CWI, -4.4°C ± 1.3°C; WBC, -1.8°C ± 1.1°C; P < 0.001) and deep (CWI, -2.9°C ± 0.8°C; WBC, -1.3°C ± 0.6°C; P < 0.001) muscle temperatures occurred immediately after CWI. Decreases in femoral artery conductance were greater after CWI (CWI, -84% ± 11%; WBC, -59% ± 21%, P < 0.02) and thigh (CWI, -80% ± 5%; WBC, -59% ± 14%, P < 0.001), and calf (CWI, -73% ± 13%; WBC, -45% ± 17%, P < 0.001) cutaneous vasoconstriction was greater after CWI. Reductions in rectal temperature were similar between conditions after cooling (CWI, -0.6°C ± 0.4°C; WBC, -0.6°C ± 0.3°C; P = 0.98).

CONCLUSION

Greater reductions in blood flow and tissue temperature were observed after CWI in comparison with WBC. These novel findings have practical and clinical implications for the use of cooling in the recovery from exercise and injury.

Neutrophil Depletion Attenuates Muscle Injury after Exhaustive Exercise

PURPOSE

The infiltration of macrophages in skeletal muscle during exhaustive exercise promotes inflammation, myofiber lesion, and muscle injury. Although neutrophils upregulate macrophage infiltration in skeletal muscles during exercise, the role of neutrophils in promoting muscle injury after exhaustive exercise remains unclear. In this study, we investigated the effects of preexercise neutrophil depletion with antineutrophil antibody treatment on muscle injury, inflammation, and macrophage infiltration after exhaustive exercise.

METHODS

Male C57BL/6J mice were randomly assigned to four groups, namely, sedentary with control antibody (n = 10), sedentary with antineutrophil antibody (n = 10), exhaustive exercise with control antibody (n = 10), and exhaustive exercise with antineutrophil antibody (n = 10). The mice were given intraperitoneal injection of the antineutrophil antibody (anti-Ly-6G, clone 1A8) or the control antibody (anti-Ly-6G, clone 2A3), and remained inactive or performed exhaustive exercise on a treadmill 48 h after the injection. Twenty-four hours after the exhaustive exercise, the gastrocnemius muscles were removed for histological and polymerase chain reaction (PCR) analyses. Infiltration of neutrophils and macrophages was evaluated with Ly-6G and F4/80 immunohistochemistry staining procedures. Muscle fiber injury was detected based on the number of IgG staining fiber. The mRNA expression levels of proinflammatory cytokines and chemokines were evaluated with real-time reverse transcription PCR.

RESULTS

Exhaustive exercise increased neutrophil infiltration into the gastrocnemius muscle substantially by 3.1-fold and caused muscle injury, but these effects were markedly suppressed by preexercise treatment with antineutrophil antibody (neutrophil infiltration, 0.42-fold, and muscle injury, 0.18-fold). Treatment with antineutrophil antibody also decreased macrophage infiltration (0.44-fold) and mRNA expression of tumor necrosis factor-α (0.55-fold) and interleukin-6 (0.51-fold) in the skeletal muscle after exhaustive exercise.

CONCLUSION

These results suggest that neutrophils contribute to exacerbating muscle injury by regulating inflammation through the induction of macrophage infiltration.

Local cryotherapy minimally impacts the metabolome and transcriptome of human skeletal muscle

Cryotherapy is commonly used in the treatment of skeletal muscle injuries. However, the data to support the use of cryotherapy is inconclusive, and the biochemical etiology of cryotherapy in human skeletal muscle remains largely unknown. We therefore sought to determine how a clinically-relevant dose of cryotherapy would impact the transcriptome and metabolome of skeletal muscle. Eight healthy male subjects (age 24.7 ± 4.5 years, BMI 22.2 ± 1.6) received a 15 minute bout of local cryotherapy, delivered via ice cup massage over the anterolateral thigh. This resulted in an 85% decrease in skin temperature and a predicted 27% reduction in intramuscular temperature. The contralateral side served as a non-treated control. Two hours after cryotherapy, muscle biopsies were obtained to analyze changes in the transcriptome, metabolome, and activation of p38 MAPK, ERK1/2, Akt, and p70S6K proteins. No changes were detected in the transcriptome between control and cooled muscles. Cryotherapy reduced levels of hexose sugars and hypoxanthine by 1.3%, but no statistically different changes were observed in 60 additional metabolites. Overall, no differences in phosphorylated p38 MAPK, ERK1/2, Akt, and p70S6K were observed. A clinically relevant dose of cryotherapy produced negligible acute biochemical and molecular changes in the skeletal muscle of human subjects.

Effects of Topical Icing on Inflammation, Angiogenesis, Revascularization, and Myofiber Regeneration in Skeletal Muscle Following Contusion Injury

Contusion injuries in skeletal muscle commonly occur in contact sport and vehicular and industrial workplace accidents. Icing has traditionally been used to treat such injuries under the premise that it alleviates pain, reduces tissue metabolism, and modifies vascular responses to decrease swelling. Previous research has examined the effects of icing on inflammation and microcirculatory dynamics following muscle injury. However, whether icing influences angiogenesis, collateral vessel growth, or myofiber regeneration remains unknown. We compared the effects of icing vs. a sham treatment on the presence of neutrophils and macrophages; expression of CD34, von Willebrands factor (vWF), vascular endothelial growth factor (VEGF), and nestin; vessel volume; capillary density; and myofiber regeneration in skeletal after muscle contusion injury in rats. Muscle tissue was collected 1, 3, 7, and 28 d after injury. Compared with uninjured rats, muscles in rats that sustained the contusion injury exhibited major necrosis, inflammation, and increased expression of CD34, vWF, VEGF, and nestin. Compared with the sham treatment, icing attenuated and/or delayed neutrophil and macrophage infiltration; the expression of vWF, VEGF, and nestin; and the change in vessel volume within muscle in the first 7 d after injury (P < 0.05). By contrast, icing did not influence capillary density in muscle 28 d after injury (P = 0.59). The percentage of immature myofibers relative to the total number of fibers was greater in the icing group than in the sham group 28 d after injury (P = 0.026), but myofiber cross-sectional area did not differ between groups after 7 d (P = 0.35) and 28 d (P = 0.30). In conclusion, although icing disrupted inflammation and some aspects of angiogenesis/revascularization, these effects did not result in substantial differences in capillary density or muscle growth.